1 /* $OpenBSD: cbc128.c,v 1.8 2023/07/08 14:56:54 beck Exp $ */
2 /* ====================================================================
3 * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 *
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@openssl.org.
26 *
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 */
51
52 #include <openssl/crypto.h>
53 #include "modes_local.h"
54 #include <string.h>
55
56 #ifndef MODES_DEBUG
57 # ifndef NDEBUG
58 # define NDEBUG
59 # endif
60 #endif
61
62 #undef STRICT_ALIGNMENT
63 #ifdef __STRICT_ALIGNMENT
64 #define STRICT_ALIGNMENT 1
65 #else
66 #define STRICT_ALIGNMENT 0
67 #endif
68
69 void
CRYPTO_cbc128_encrypt(const unsigned char * in,unsigned char * out,size_t len,const void * key,unsigned char ivec[16],block128_f block)70 CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
71 size_t len, const void *key,
72 unsigned char ivec[16], block128_f block)
73 {
74 size_t n;
75 const unsigned char *iv = ivec;
76
77 #if !defined(OPENSSL_SMALL_FOOTPRINT)
78 if (STRICT_ALIGNMENT &&
79 ((size_t)in|(size_t)out|(size_t)ivec) % sizeof(size_t) != 0) {
80 while (len >= 16) {
81 for (n = 0; n < 16; ++n)
82 out[n] = in[n] ^ iv[n];
83 (*block)(out, out, key);
84 iv = out;
85 len -= 16;
86 in += 16;
87 out += 16;
88 }
89 } else {
90 while (len >= 16) {
91 for (n = 0; n < 16; n += sizeof(size_t))
92 *(size_t *)(out + n) =
93 *(size_t *)(in + n) ^ *(size_t *)(iv + n);
94 (*block)(out, out, key);
95 iv = out;
96 len -= 16;
97 in += 16;
98 out += 16;
99 }
100 }
101 #endif
102 while (len) {
103 for (n = 0; n < 16 && n < len; ++n)
104 out[n] = in[n] ^ iv[n];
105 for (; n < 16; ++n)
106 out[n] = iv[n];
107 (*block)(out, out, key);
108 iv = out;
109 if (len <= 16)
110 break;
111 len -= 16;
112 in += 16;
113 out += 16;
114 }
115 memmove(ivec, iv, 16);
116 }
117 LCRYPTO_ALIAS(CRYPTO_cbc128_encrypt);
118
119 void
CRYPTO_cbc128_decrypt(const unsigned char * in,unsigned char * out,size_t len,const void * key,unsigned char ivec[16],block128_f block)120 CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
121 size_t len, const void *key,
122 unsigned char ivec[16], block128_f block)
123 {
124 size_t n;
125 union {
126 size_t t[16/sizeof(size_t)];
127 unsigned char c[16];
128 } tmp;
129
130 #if !defined(OPENSSL_SMALL_FOOTPRINT)
131 if (in != out) {
132 const unsigned char *iv = ivec;
133
134 if (STRICT_ALIGNMENT &&
135 ((size_t)in|(size_t)out|(size_t)ivec) % sizeof(size_t) !=
136 0) {
137 while (len >= 16) {
138 (*block)(in, out, key);
139 for (n = 0; n < 16; ++n)
140 out[n] ^= iv[n];
141 iv = in;
142 len -= 16;
143 in += 16;
144 out += 16;
145 }
146 } else if (16 % sizeof(size_t) == 0) { /* always true */
147 while (len >= 16) {
148 size_t *out_t = (size_t *)out,
149 *iv_t = (size_t *)iv;
150
151 (*block)(in, out, key);
152 for (n = 0; n < 16/sizeof(size_t); n++)
153 out_t[n] ^= iv_t[n];
154 iv = in;
155 len -= 16;
156 in += 16;
157 out += 16;
158 }
159 }
160 memmove(ivec, iv, 16);
161 } else {
162 if (STRICT_ALIGNMENT &&
163 ((size_t)in|(size_t)out|(size_t)ivec) % sizeof(size_t) !=
164 0) {
165 unsigned char c;
166 while (len >= 16) {
167 (*block)(in, tmp.c, key);
168 for (n = 0; n < 16; ++n) {
169 c = in[n];
170 out[n] = tmp.c[n] ^ ivec[n];
171 ivec[n] = c;
172 }
173 len -= 16;
174 in += 16;
175 out += 16;
176 }
177 } else if (16 % sizeof(size_t) == 0) { /* always true */
178 while (len >= 16) {
179 size_t c, *out_t = (size_t *)out,
180 *ivec_t = (size_t *)ivec;
181 const size_t *in_t = (const size_t *)in;
182
183 (*block)(in, tmp.c, key);
184 for (n = 0; n < 16/sizeof(size_t); n++) {
185 c = in_t[n];
186 out_t[n] = tmp.t[n] ^ ivec_t[n];
187 ivec_t[n] = c;
188 }
189 len -= 16;
190 in += 16;
191 out += 16;
192 }
193 }
194 }
195 #endif
196 while (len) {
197 unsigned char c;
198 (*block)(in, tmp.c, key);
199 for (n = 0; n < 16 && n < len; ++n) {
200 c = in[n];
201 out[n] = tmp.c[n] ^ ivec[n];
202 ivec[n] = c;
203 }
204 if (len <= 16) {
205 for (; n < 16; ++n)
206 ivec[n] = in[n];
207 break;
208 }
209 len -= 16;
210 in += 16;
211 out += 16;
212 }
213 }
214 LCRYPTO_ALIAS(CRYPTO_cbc128_decrypt);
215